Email is not going to disappear. Possibly ever. Until the robots kill us all.
Google is about information and computers and making things really fast. Facebook is about the sharing and connections. These missions give these companies direction and motivation.
Cultures that don't laugh at themselves are cults.
I like writing code. I like building product. I like making things that people like.
Bitcoin may be the TCP/IP of money.
If everything you do works, then you're not taking many risks and probably aren't innovating either.